Copolymers of tetrahydrofuran and cyclic anhydrides are known in the art. These polymers were made with the use of a Lewis acid catalyst such as an organoaluminum compound or an onium compound, optionally in the presence of a cocatalyst, see for example J. Habermeier, et al., J. Polym. Sci., Part C, p. 2131-2141 (1967). No mention is made in this paper of metal perfluoroalkylsulfonates as catalysts.
S. L. Borkowsky, et al., Organometal., vol. 10, p. 1268-1274 (1991) report that certain zirconium complexes can initiate the polymerization of tetrahydrofuran. No mention is made of zirconium perfluoroalkylsulfonates, or of copolymers.
U.S. Pat. No. 3,842,019 describes the polymerization of oxiranes and other small ring compounds by a presumed cationic mechanism, using as the catalyst the decomposition products of metal perfluoroalkyl sulfonates. These catalysts are described as "latent", that is no reaction occurs until the metal salt is decomposed. The reactions reported are relatively slow, even at elevated temperatures.
U.S. Pat. Nos. 5,084,586 and 5,124,417 describe the cationic polymerization of various monomers, including cyclic ethers, using onium cations, whose corresponding anions are fluororalkylsulfatometallates. Onium ion catalyzed cationic polymerizations are well known, and there is no mention in these patents of the use of metal salts not containing onium ions, such as metal triflates, as catalysts for the polymerization of cyclic ethers.
German Patent application 2,459,163 describes the polymerization of THF using a combination of ferric chloride and carboxylic anhydride as catalyst.
G. A. Olah, et al., J. Appl. Polym. Sci., Vol. 45, 1355-1360 (1992) describe the use of boron, aluminum and gallium tristriflate to catalyze the polymerization of THF.